Under a load of 16 simultaneous requests, the RAID0 arrays increase their speed in response to higher writes percentages and provide a nice scalability as concerns the number of disks per array. The mirrored arrays – RAID1 and RAID10 – are again faster than the JBOD and the two-disk RAID0, respectively, and again, save for the Random Write mode. Unlike in the write-through mode, however, their speeds only decrease till 80% writes, but then start to grow. This seems to be the result of the controller optimizing write requests. This is also why the RAID5 arrays lost their speeds just a little at 70% writes and even sped up somewhat at 80% writes. I’d also like to note that the RAID5 arrays showed different speeds in the Random Read mode, at last, but this difference diminished later and vanished completely at 70% writes. That’s again a mysterious phenomenon.

Under a workload of 256 requests, the three-disk RAID0 slows down when there are many writes to be performed. The RAID5 arrays don’t have that sharp curve in their graphs when the writes percentage is high. Otherwise, it’s all the same as under a workload of 16 requests.